1. Field of the Invention
The present invention relates to a portable forced air heater for heating occupied space, which heater projects heat radially universally in all horizontal directions from the heater in a three hundred sixty degree pattern. The heater has removable and adjustable shields for limiting heat propogation to less than the three hundred sixty degree pattern, so that objects near the heater will not be exposed to excessive heat.
2. Description of the Prior Art
Portable forced air heaters are known in the prior art. Such heaters generally include a heat source and a fan forcing air past the heat source and into a room or other space being heated. Depending upon the precise nature of the heater, heated air may be ejected in a selected direction, in several directions, or throughout an angle encompassing many different directions. The latter possibility includes three hundred sixty degree discharge.
Certain situations are most advantageously addressed by providing three hundred sixty degree discharge, such as heating of the room of a building by a heater centrally located within that room. The prior art has provided heaters having this feature.
U.S. Pat. No. 3,229,070, issued to Orville C. Wells on Jan. 11, 1966, describes a portable heater having a three hundred sixty degree dispersion pattern of heated forced air. A frustoconical structure guides incoming air into a blower located below. In contrast to this invention, wherein the discharge pattern of heated air is fixed, the present invention makes provision for optionally blocking discharge in selected directions. Another difference is that the air flow through the respective heaters is different. Wells draws air from above, whereas the present invention draws air from its lowermost periphery.
Portable heaters having heat dispersed through a three hundred sixty degree pattern, each including a conical structure deflecting forced heated air, are shown in U.S. Pat. Nos. 1,900,956, issued to William W. Somersall on Mar. 14, 1933, and 5,245,692, issued to Yuzou Kawai on Sep. 14, 1993. In contrast to the present invention, both Kawai and Somersall lack means for modifying or limiting their respective heat dispersion patterns. Also, neither Somersall nor Kawai insulates his conical structure as is performed in the present invention. Rather, in a departure from the practice of the present invention, Somersall intentionally passes some of the heat through the conical structure to expedite evaporating water for humidification. Kawai locates his conical structure within the air stream prior to heating, unlike the present invention. Kawai also draws air through his heater in a direction opposite that of the present invention.
U.S. Pat. No. 3,775,590, issued to William Joseph Gartner on Nov. 27, 1973, sets forth a portable forced air heater wherein heat is discharged radially and horizontally through a three hundred sixty degree pattern. However, unlike the present invention, Gartner makes no provision for limiting the discharge pattern.
An industrial facility heater is shown in U.S. Pat. No. 4,103,146, issued to John F. Rampe on Jul. 25, 1978. This heater has a significant characteristic that it heats spaces having high ceilings, and accomplishes this by moving a relatively great volume of heated air. A significant effect of this invention is to redistribute a heated stratum of air which would otherwise accumulate at the ceiling. The apparatus includes a vertically oriented square or rectangular air shaft. Large areas of the uppermost and lowermost sections of the air shaft are formed by screened panels, so that there is no solid walled air conduit. Air is discharged horizontally through four parallelepiped faces of the upper sections of the air shaft. Make-up air migrates radially toward the bottom of the air shaft to complete a cycle.
It should be noted that this scheme successfully causes an air flow of great volume, but does not truly disperse the air throughout a three hundred sixty degree pattern. Rather, the dispersion pattern is cruciform. By contrast, the dispersion pattern of the present invention describes a full three hundred sixty degree pattern. In another departure from the device of Rampe, the present invention has provision for optionally blocking discharge in selected directions. As Opposed to the present invention, the discharge pattern of Rampe is fixed.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.